Stretch laminates can be used in a wide variety of disposable absorbent articles. For example, in order to provide a disposable absorbent diaper which can fit a range of wearers and minimize leaks, disposable absorbent diapers often include stretch laminates. Because the wearers of disposable absorbent diapers vary in size, stretch laminates are often used in the waist region and leg regions of the disposable absorbent diaper, thereby allowing the disposable absorbent diaper to fit a wide range of wearers.
A conventional stretch laminate often has at least two nonwoven materials and at least one elastic film sandwiched between the two nonwoven materials. In general, the two nonwoven materials are attached to the elastic film via an adhesive.
In some cases, stretch laminates used in disposable absorbent articles are mechanically activated. The mechanical activation process can involve meshing the stretch laminate between activation rolls which have protruding teeth. Typically, an activation region of the stretch laminate is intermeshed between the teeth of the activation rolls as the stretch laminate passes through the activation rolls. A tack down region disposed outboard of the activation region typically is not intermeshed between the protruding teeth of the activation rolls. Because the activation region of the stretch laminate is intermeshed between the teeth of the activation rolls, the nonwoven materials are permanently elongated at least to a certain degree, so that upon release of the applied tensile forces, the stretch laminate generally will not fully return to its original undistorted configuration. Such orientation and alignment is common throughout the industry.
This process of making a stretch laminate elastically extensible is called “mechanical activation” or “ring rolling”. The mechanical activation process is typically performed at high speeds. Consequently, the stretch laminate experiencing the mechanical activation process can be exposed to very high strain rates. Moreover, in order to provide the stretch laminate with greater extensibility, the stretch laminate may further be exposed to high percentages of strain which, in turn, can also increase the strain rate experienced by the stretch laminate in the mechanical activation process.
Unfortunately, many stretch laminates may incur defects, in part, as a result of the high strain rates and high percentages of strain experienced during the mechanical activation process. Many of the defects are structural in nature. For example, an elastic film which undergoes the mechanical activation process may experience defects such as holes which reduce the structural integrity of the elastic film. The reduction of the structural integrity of the elastic film can lead to premature failure of the stretch laminate.
Consequently, it would be beneficial to provide a stretch laminate which exhibited reduced defects from the mechanical activation process. Additionally, a process for creating a stretch laminate which can withstand the mechanical activation process and exhibit reduced defects therefrom is needed.